This a core mod for future updates of my mod, but can also be used by other developer.
There are different NBT Tags that changes the player's attributes those can be changed using commands or the mcreator number nbt tag block.
Attributes as nbt tag:
DC_BaseHealth : base health of the player [Default 20]
DC_BaseLuck : base luck of the player [Default 0]
DC_BaseAcceleration : haste [Default 0]
DC_BaseSpeed : Walking Speed [Default 0.10000000149011612]
DC_BasePower : strength [Default 0]
DC_BaseGravity : gravity of the player, if negative player will float [Default: 0.08]
DC_BaseWaterSpeed : swimming speed [Default 1]
DC_BaseHeatThreshold : this is for a future version of the dangerous temperatures mod, tell the mod how much heat a player can deal with [Default 10]
DC_BaseColdThreshold : same but with cold [Default 10]
DC_BaseReach : Reach of the player [Default 5]
Change by command:
/manipulate DC_NBTTag 10
To give things like health boosts or anything like that on items simply tag that item with "forge:amplify_stats"
then add one or multiple of these nbt number tags:
Only is applied when item is in hand or equiped.